🔧 Yukon - Serpentine Belt Replacement

The serpentine belt drives key accessories like the alternator, A/C compressor, and power steering. Replacing it is mostly about safely relieving the belt tension, routing the new belt correctly, and verifying it’s fully seated on every pulley.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine; keep hands away from hot pulleys and the radiator fan.
• ⚠️ Keep fingers and tools clear of belt/pulleys; never “bump” the starter during this job.
• ⚠️ If you disconnect the battery, remove the negative cable first to reduce short risk.
• ⚠️ Double-check belt routing before starting; misrouting can damage accessories.

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🔧 Required Tools

You'll need the following tools for this repair:

• 15mm socket
• 3/8" drive ratchet
• 3/8" drive breaker bar
• 6" socket extension (3/8" drive)
• Trim removal tool
• Flashlight
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Serpentine belt - Qty: 1
• Serpentine belt tensioner (optional but recommended if noisy/weak) - Qty: 1
• Idler pulley (optional if noisy/rough) - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Let the engine cool fully.
• Use a flashlight to locate the belt routing diagram (often on a sticker in the engine bay). If it’s missing, take a clear photo of the current routing before removal.
• Tip: Draw the routing on paper first.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Use a trim removal tool and your hands to carefully lift the cover straight up (it’s held by rubber grommets on most setups).
• Set the cover aside where it won’t get stepped on.

Step 2: Locate the belt tensioner

• Use a flashlight to find the belt tensioner (spring-loaded arm with a smooth pulley).
• Identify the 15mm hex on the tensioner arm (this is where you rotate it to release tension).
• A “tensioner” is a spring-loaded part that keeps the belt tight automatically.

Step 3: Relieve belt tension

• Install the 15mm socket on a 3/8" breaker bar (use a 6" extension if it helps reach).
• Rotate the tensioner smoothly to release belt tension (it will feel strong—this is normal).
• Tip: Move slowly; don’t let it snap back.

Step 4: Remove the old belt

• While holding the tensioner rotated with the breaker bar, slide the belt off the easiest-to-reach top pulley using your free hand.
• Carefully let the tensioner return to its resting position (do not release it suddenly).
• Remove the belt from the remaining pulleys and out of the engine bay.

Step 5: Inspect pulleys and tensioner before installing the new belt

• Use a flashlight and your gloved hand to spin the idler pulley(s) and tensioner pulley.
• They should spin smoothly and quietly. If you feel grinding, wobble, or hear squealing, plan to replace that pulley/tensioner.
• Check for oil or coolant on pulleys; leaks can ruin a new belt quickly.

Step 6: Route the new belt correctly

• Match the belt routing diagram (or your photo) and lay the new belt around the lower pulleys first (hardest to reach).
• Make sure the belt ribs sit fully inside the ribbed pulleys, and the smooth side rides on smooth pulleys.
• Leave one easy-to-reach upper pulley for last.

Step 7: Apply tension and slip the belt onto the final pulley

• Use the 15mm socket and breaker bar to rotate the tensioner again.
• Slip the belt over the last pulley, then slowly release the tensioner back into place.
• Visually confirm the belt is centered and seated on every pulley groove.
• Tip: One rib off will shred the belt.

Step 8: Reinstall the engine cover

• Align the cover with the mounting points and press down evenly by hand until it snaps into the grommets.

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✅ After Repair

• Do a final visual sweep with a flashlight: belt fully seated, tools removed, nothing left in the engine bay.
• Start the engine and watch the belt for 20-30 seconds. It should run smoothly with no wandering or squealing.
• If you hear chirping/squeal right away, shut it off and re-check belt routing and seating.

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💰 DIY vs Shop Cost

Shop Cost: $150-$300 (parts + labor)

DIY Cost: $30-$90 (parts only)

You Save: $120-$210 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.

Assumption: Stock accessory drive layout for your Yukon’s 6.2L.